Where is the Bird's Nest? (２匹のヒナドリの巣, Nibiki no Hinatori no Su, lit. Two Chicks in a Nest) is a secondary event in Tomba! 2: The Evil Swine Return. This is the second event involving two colored birds, which will be more important later in the game.
Find the bird nest belonging to the chicks in Town of the Fishermen.
This event will be activated when the both chicks have been obtained in the previous event. If you aren't there already, you need to go to the background using the seesaw barrels.
When you are there, go to the left until you find a tree. Climb all the way up to the top and the two chicks will jump into the bird nest which is there. The event is cleared.